"We're back into a bit of a cooler southwest feed of air, which is going to bring some showers, but the showers become few and far between through the weekend," Mr Law said.
Southland and Otago could also expect some heavy showers, following today's drop in temperatures and forecast of snowfall in some high roads in Fiordland.
"But we should see things start to improve through the day time, with more sunshine, and showers becoming more isolated, and they should start to clear as we head in towards Saturday," Mr Law said.
"After that it looks pretty good, high pressure starts to build across. For Saturday and Sunday you might have a few showers here and there, but most of the time it's looking fine, some good spells of sunshine - not as hot as it has been. But I think it is looking like a pretty decent weekend, and we keep hold of plenty of dry weather as we go through in towards Sunday."
Overall, it "shouldn't be a bad story", Mr Law said, just a little more cloud around and cooler temperatures than the past few weeks.
Christchurch has already experienced a sudden change in temperature, with the mercury dropping to 3C overnight, almost 25C lower than the city's maximum on Wednesday, Mr Law said. The Garden City will remain a cool 16C for Waitangi Day, before jumping to 25C on Saturday.
But it's good news for rugby fans travelling to Wellington for the Sevens, as Mr Law said the city looks "pretty good" for kick off tomorrow.
"It's a cooler southerly so the temperatures here in the capital are around 16C-17C, plus the southerly, but it should be a case of any showers being very early in the morning [on Friday] or very late in the night towards Saturday morning."
Earlier this week, MetService said the start to February would see a cooler southwesterly change, bringing some welcome relief from the extreme heat of January and some much needed rain to dry areas across the country.
But MetService predicted a drier than normal February for the South Island, as the highs return next week, and above normal rainfall for Northland, and possibly Auckland and Coromandel.
MAIN CENTRES FORECAST:
* Whangarei - Cloudy periods with the chance of a shower, a strong southeasterly and a high of 24C. Fine spells on Saturday, the southerly will die out and a high of 24C. Sunday will be fine with light winds and a high of 25C.
* Auckland - Cloudy periods and a few showers on Friday, with a strong southwest wind and a high of 22C. Saturday will see fine spells with a chance of morning showers, the southerly dies out, and a high of 23C. Fine on Sunday, with light winds, and a high of 24C.
* Hamilton - Showers clearing by early afternoon, then fine, with a strong southwesterly, and a high of 22C. Mainly fine on Saturday, with morning and evening cloud, light winds and a high of 24C. Cloudy periods on Sunday, with a few showers and westerly breezes, a high of 25C.
* Tauranga - A few morning showers then fine, with gusty southwesterlies, and a high of 23C. Fine on Saturday, apart from some morning cloud, light winds and a high of 24C. Sunday will be fine again, with some evening cloud, westerly breezes and a high of 26C.
* Wellington - Fine with cool southerlies, and a high of 16C. Cloudy periods on Saturday, the southerly dies out and a northerly develops, expect a high of 20C. Sunday will have cloudy periods and strong northerlies, a high of 22C.
* Christchurch - Fine on Friday, with strong southwesterlies and a high of 16C. Saturday will be fine, with the southerly dying out and a high of 24C. Fine again on Sunday, with northwesterlies developing and a high of 25C.
* Dunedin - A few showers and cold southwesterlies, a high of 13C. Morning cloud on Saturday, turning fine with southwesterlies and a high of 23C. Sunday will be fine with high cloud, the southwesterly dying out turning to a northeasterly later, and a high of 25C.
